The diagram on the right illustrates the dimensions of a CHOCBOX.
All measurements are in milimeters. The illustration is not to scale:

90mm x 50mm x 30mm

Technical Specs  
Item:   CHOCBOX Inline Connector / Junction Box.
A plastic box to insulate connector blocks
Used as a junction box for fixed wiring
Used as an inline connector when used with cord grips supplied.
Dimensions: 90mm x 50mm x 30mm.
Test Specifications:
Partial test to appropriate Clauses of BS4533: section 102.1:1990/EN60 598-2-1:1989 in respect of cable restraint and flammability of material.
Cable Restraint:
The cable restraint clamping screws were tightened and loosened 5 times at 0.6n torque. No damage occured impairing further use of the screws. Cable retraints withstood a pull-force 60N, applied 25 times.
Flammable Material:
The sample material was subjected to the 650 degree glow-wire test of Sub-clause 13.3.2 of BSEN60598-1 using the test apparatus and test procedure described in IEC 695-2-1:1990 (fire hazard testing for electrotechnical products) After testing, the sample was examined with respect to 650 degree glow-wire test covers, shades and similar parts not having an insulation function referred to in Clause 4.15 of BSEN60598-1.
Pertinent IEE regs: 422-01-04 referring to 526-03-02.