I've asked before about this, and got a very confusing answer back. I'll forward you the emails Cosie.
This is the list of LRP cells, without getting a tape measure out I can't say what's what,
http://www.s-m-d.co.uk/car-c100108.html
but to back that up
LRP79821LRP VTEC LiPo Competition car line 1800 - 7,4V / 28C1 piece£47.9987 x 33,5 x 19mm89,5g
LRP79831LRP VTEC LiPo Competition car line 1300 - 11,1V / 28C1 piece£53.9987 x 33,5 x 19mm91,5g
LRP79862LRP VTEC LiPo Competition car line 5300 - 7,4V / 28C1 piece£99.99137.5 x 46.5 x 43.5mm282g
LRP79880LRP VTEC LiPo Competition car line 3600 - 11,1V / 28C1 piece£99.99137,5 x 46,5 x 23,5mm284g