Alpha | 1/4in Locking Extension Bar Set 4 Piece 300mm | High Carbon Steel
The Alpha Pro Lock TS08-EXT300LS4 is a four-piece locking extension bar set with 300mm extensions, rated 1/4 inch drive for impact drivers and drills. The TS08-EXT300LS4 features a mechanical lock-and-twist design that holds bars together securely without slipping. Each extension locks to the next, allowing the set to reach up to 1,200mm total when fully assembled.
Roof cavities, wall cavities, and confined spaces often force electricians into awkward overhead work with standard drill bits. A compact extension set that can stack to full height while remaining slim enough for tight openings is essential. The TS08-EXT300LS4 solves this by stacking four 300mm bars to reach into deep ceiling voids without needing longer, heavier single extensions that take up truck space and catch on edges during pull-back.
Sparkies and construction workers value the TS08-EXT300LS4 because it fits the 15mm hole in standard Australian wall frames, locks without wobble, and holds fast through twisting stress. The high-carbon-steel construction and threadlock mechanism mean no dropped pieces down the wall once locked together. Stock rotation is simple since the kit comes complete, and the included heavy-duty carry case keeps the set organised on the truck.
Features
- Four 300mm extensions — stack together to reach 1,200mm total length for deep cavity drilling without single-long extensions.
- 1/4 inch drive compatibility — works with all common 1/4 inch impact driver bits, drill chucks, and hex-bit holders rated for the drive size.
- Locking mechanism — secure twist-lock and threadlock system holds extensions together under load with no rattle or creep during drilling.
- Slim 15mm design — fits through standard 15mm Australian wall-cavity openings and overhead ceiling holes without binding or twisting sideways.
- High-carbon-steel construction — rated for torque stress from impact drivers, with no flex or bending under normal use even in confined spaces.
- Threadlock prevents loosening — extensions do not come loose during use or storage, reducing risk of dropping bars inside walls or roofs.
- Heavy-duty plastic carry case supplied — keeps all four bars organised and protected on the truck, taking the guesswork out of what you've got in the kit.
- No tool changes needed — swap extensions in seconds without changing driver or changing hand position; works with 1/4 inch bits and hex drivers already on board.
- Compact storage footprint — the case takes up less room in a tool bag or truck drawer than four separate single extensions of the same total reach.
- Jobsite-tested lock design — the mechanical lock does not depend on spring clips or friction only; the twist-lock actively clamps each bar to the next one.
Where to use
- Ceiling void drilling — the TS08-EXT300LS4 reaches into roof and ceiling cavities for wiring, sensor, and speaker installations without wrestling single long extensions.
- Wall cavity wiring runs — reaches into deep stud bays and cavity spaces for conduit and cable runs during pre-wiring and renovations.
- Overhead electrical work — supports vertical drilling for downlights, exhaust fans, and smoke alarms mounted in high ceilings where reach and control are tight.
- Internal wall conduit boring — reaches through internal walls and party walls for tight access points where a single long extension would twist or catch.
- Confined-space access points — the slim 15mm profile fits through small openings and tight joist spaces where thicker or longer single bars get stuck.
- Impact driver extension work — rated for impact driver torque, making it suitable for driving fasteners through long reach as well as drilling holes in confined locations.
- Renovation and retrofit jobs — stackable design means electricians can fit the exact reach needed for each job without carrying multiple extension sizes.
- Quick-access jobsite kit — the supplied case keeps all four bars together and ready to grab for any hole-drilling task that needs vertical or horizontal reach into tight voids.
The Alpha Pro Lock TS08-EXT300LS4 is not suitable for impact-driven fastening through solid materials (concrete, steel) at maximum depth; use shorter, thicker single extensions for high-impact foundation work. The 15mm slim design is optimised for cavity and wall access, not for brute-force drilling in dense materials where longer extensions need maximum rigidity.
Verified Sparky Direct customer reviews: Pro Lock TS08-EXT300LS4 (TS08-EXT300LS4)
"Pretty solid kit. Works as expected. Good price." — Andrew
"Excellent quality. Very practical. Awesome service" — Dave M
"Excellently packaged. Excellent quality. Love the product" — SPARKED
