first and second parts 30 32 attachable around the strap 12 with a means to secure attach or join the first and second parts to the strap fig6 discloses the first part 30 being situated on an upper side of the strap 12 and the second part 32 being situated on a lower side of the strap 12 fig2 and 4 disclose a channel 34 formed between the first part 30 and the second part 32 the channel 34 accommodating the strap 12 the channel 34 is preferably formed by a lengthwise recess in each of the first and second parts 30 32 in other embodiments a deeper recess in only one of the first part 30 or the second part 32 could provide the channel 34 as disclosed in fig2 and 4 an inner volume of the channel 34 is larger than the volume of the strap 12 so as to define an air space between the insulating material 18 and the strap 12 fig4 and 6 disclose lands 36 within the channel 34 which are provided to give positive contact between the first and second parts 30 32 and the strap 12 for structural integrity the air space provides additional insulation against thermal conductivity from the strap 12 into the insulating material 18 as disclosed in fig1 and 4 the first and second parts 30 32 are not touching along a periphery of each so as to define a peripheral gap.